Deep-rooted maize plants utilize water and nutrients more effectively, particularly in compacted soil. However, the mechanisms by which different maize genotypes adjust root angles in response to compaction remain underexplored. We conducted a two-year study (2021-2022) on silty loam soils in the North China Plain. We tested two genotypes of maize [one with naturally deep roots (DR) and another with shallow roots (SR)] in compacted (C) and non-compacted (NC) soil. Soil compaction impeded shoot growth in both genotypes; however, DR exhibited better growth than SR. Under compacted conditions, DR maintained steeper root angles and demonstrated superior mechanical strength with larger root cortex areas (increased by 60 %) and stele (increased by 92 %), as well as higher cellulose concentration (up to 146 %). Notably, PIEZO1 gene expression increased significantly (up to 242 %) in DR under compaction, suggesting its role in root structural enhancement, unlike in SR where it remained unchanged. These findings underscore the importance of genetic, anatomical, and biochemical adaptations in maize roots, facilitating their resilience to soil compaction. Such insights could inform the breeding of maize genotypes that are better adapted to diverse soil conditions, potentially boosting agricultural productivity.

Soil compaction caused by heavy agricultural machinery poses a significant challenge to sustainable farming by degrading soil health, reducing crop productivity, and disrupting environmental dynamics. Field traffic optimization can help abate compaction, yet conventional algorithms have mostly focused on minimizing route length while overlooking soil compaction dynamics in their cost function. This study introduces Soil2Cover, an approach that combines controlled traffic farming principles with the SoilFlex model to minimize soil compaction by optimizing machinery paths. Soil2Cover prioritizes the frequency of machinery passes over specific areas, while integrating soil mechanical properties to quantify compaction impacts. Results from tests on 1000 fields demonstrate that our approach achieves a reduction in route length of up to 4-6% while reducing the soil compaction on headlands by up to 30% in both single-crop and intercropping scenarios. The optimized routes improve crop yields whilst reducing operational costs, lowering fuel consumption and decreasing the overall environmental footprint of agricultural production. The implementation code will be released with the third version of Fields2Cover, an open-source library for the coverage path planning problem in agricultural settings.

Forest logging activities negatively affect various soil properties. In this study, we focus on the logging effects on soil water retention and associated pore size distribution. We measured the soil-water characteristic curves (SWCCs) on 21 undisturbed samples from three research plots: a reference area, a clear-cut area and a forest track. A total of 12 SWCC points between saturation and wilting point were determined for each sample with a sand box and pressure plate apparatus. The trimodal behaviour is highlighted by the dependence between soil moisture and suction. Therefore, we proposed a revised model by combining two exponential expressions with the van Genuchten model. The exponential terms describe the influence of macro-and-structural porosities, and the latter is used to calculate textural porosity. This new model with eight independent parameters was suitable to fit trimodal SWCCs in all samples. Results revealed that logging had the most destructive effect on large pores, and the soil on the forest track was the most affected. Both soil-air and available water capacity were reduced and the permanent wilting point increased as a result of damage to the soil structure and pore system. Observed increased organic carbon content in compacted soils can be attributed to slowed decomposition due to reduced air capacity and increased waterlogging susceptibility of damaged soils.

Soil compaction has been found to deform soil structures and alter water flows. Although previous studies have suggested that a load exceeding the critical stress, determined by static load application, can be applied for a short duration without causing substantial damage to the soil structure, the immediate consequences of short loading times on structural integrity and the subsequent influence on soil water flow remain relatively underexplored. The principal objective of this research was to explore the effects of loading intervals, ranging from 0.1 to 2.5 s, commonly used by vehicles and machinery in the agricultural sector, on the changes in water-stable aggregates and saturated hydraulic conductivity (K-sat) associated with soil compaction, thereby enhancing our understanding of how transient external forces could affect the soil properties. Four distinct soils with varying soil organic matter (SOM) contents (13, 43, 77, and 123 g/kg) were collected from a typical Mollisol area in Northeast China, each characterized by different initial gravimetric soil water contents of 11%, 15%, 19%, and 24%, respectively. Under an applied load of 4.0 kg/cm(2), the short loading time resulted in an increase in small macroaggregates (SMAs) and a decrease in microaggregates within the distribution of water-stable aggregates, whereas it did not affect aggregate stability. K-sat decreased significantly (p < 0.05) as the loading time increased from 0.1 to 2.5 s. The effects of loading time and SOM on water-stable aggregates with particle sizes exceeding 0.25 mm, mean weight diameter, geometric mean diameter, and K-sat were identified as statistically significant or highly significant (p < 0.05 or p < 0.01). Notably, the initial soil water content remained unchanged during the short compaction period. A significant negative correlation was identified between SMAs and K-sat for each soil, with the loading time and initial soil water content (correlation coefficients ranging from -0.834 to -0.622). The results, combined with the structural equation modeling analysis, indicated that both a short loading time and SOM could directly increase SMA and decrease K-sat, with both factors influencing K-sat through SMA during the soil compaction process. This suggests that the loading time and SOM during a short duration under the same external force, rather than initial soil water content, can determine the potential degradation of the soil.

Soil compaction by agricultural machinery in general by and tractors in particular is an important problem in modern agricultural production. Such compaction destroys the soil structure, creates unfavorable physical parameters of the soil, and as a result, reduces crop yields. Therefore, it is important to clearly establish how the tractor wheels affect the soil. The experiments were conducted on the sandy loam soil by using CLAAS Xerion 5000 tractor with TRELLEBORG IF 900/60 R42 tires with internal pressures varying from 0.08 to 0.24 MPa in 0.04 MPa increments. To determine the stress propagation a developed simulation model was adapted to the parameters of the tractor in use. The iterative method was used for the numerical determination of the soil stress state. The impact of soil compaction starting from a 40 cm depth is not noticeable following the tractor's pass. In fact, from a depth of 40 cm, the normal stresses reach equilibration according to the developed mathematical model. From a depth of 20 cm, the soil compaction pattern is similar for all tire widths tested. Tires with a width up to 10 cm, 0.92 m wide tires compact the soil 25.4% less on average than tires with a width up 0.872 m wide tires. To the depth of 20 cm, tires with a width up the 0.92 m wide tires compact the soil 18.9% less on average than the tires with a width up 0.872 m, and to a depth of 30 cm - only 5.1% less. The tractor with a working tire width of 0.92 m and an axle load of 119.5 kN generate contact stresses on the field surface of up to 150 kPa, which is a permissible load for soil structure safety. Thus, the suggested simulation model of the soil stress state is suitable for use, and studies and modeling advance the idea that using wider tires results in a more equitable distribution of loads. The proposed model for analyzing stress propagation in soil enables to estimate the potential adverse impacts of wheeled or tracked agricultural machinery on soil structure by assessing stress levels that may disrupt or damage soil integrity, with the stresses varying according to the specific physical and chemical properties of each soil type.

Rapid population growth and increased use of agricultural technology have exacerbated agrarian problems. While mechanization has improved agricultural production, the use of heavy machinery for planting, irrigation, and harvesting has resulted in soil compaction. Soil compaction reduces pore space and increases soil bulk density, which hinders plant growth. Globally, automated agriculture has reduced crop production by more than 50%. In developing countries, grazing animals in crop fields increases soil compaction. Soil compaction hinders root penetration, nutrient absorption, and water infiltration, increasing the risk of soil erosion and runoff. The study investigates novel ways to reduce soil compaction, namely the utilization of nanoparticles (NPs) and nanotechnology (NT). NPs have unique qualities that can improve the mechanical properties of soil, increase its strength, and minimize compaction. Some of the NPs such as Carbon nanotubes, nanolites, nanosilica, and nanoclay have been demonstrated to increase soil fertility, water retention, and structural stability. NPs can reduce environmental pollutants while improving soil quality. However, questions about their long-term biodegradability, ecological toxicity, and health effects require further investigation. The study also addressed how NPs affect the environment and human health. Their small size raises concerns about potential exposure and toxicity to individuals and ecosystems. The paper also briefly discusses the economic and regulatory considerations related to the production, use, and disposal of NPs, emphasizing the need for comprehensive legislation, environmental impact studies, and stakeholder involvement in decision-making. Although NPs offer promise for sustainable agriculture practices, more research is necessary to optimize their use and ensure long-term safety, as well as to gain a better understanding of their unique interactions with soil physics.

Thirty-two% of European soils are thought to suffer soil structural damage by compaction. Temperate agricultural grasslands are particularly vulnerable. Larger vehicles, coupled with extended periods of grazing, and greater soil moisture, result in soil compaction: a component of poor soil health. This reduction in soil health reduces yields and increases emissions of nitrous oxide (N2O) from N application. As grass swards are not tilled regularly, mechanical improvement of structure is restricted. We assessed two non-inversion methods of grassland soil alleviation: mechanical slitting of the surface and shallow soil lifting. These were tested on two contrasting soils (sandy, free draining and silty clay loam, imperfectly drained) for dry matter (DM) yields over three annual silage cuts and emissions of N2O. Alleviation decreased soil bulk density, especially for the clay soil, but gave limited improvement in yield; as the sward lifter reduced the first cut DM yield for both soil types. N2O emissions were enhanced by alleviation, especially, the sandier soil, up to 94% more than the uncompacted control with implications for the potential short-term release of N2O from grassland, (up to 243 kg) associated with improvements to the physical aspects of soil health, for a 150 ha dairy farm.

Precompression stress, compression index, and swelling index are used for characterizing the compressive behavior of soils, and are essential soil properties for establishing decision support tools to reduce the risk of soil compaction. Because measurements are time-consuming, soil compressive properties are often derived through pedotransfer functions. This study aimed to develop a comprehensive database of soil compressive properties with additional information on basic soil properties, site characteristics, and methodological aspects sourced from peer-reviewed literature, and to develop random forest models for predicting precompression stress using various subsets of the database. Our analysis illustrates that soil compressive properties data primarily originate from a limited number of countries. There is a predominance of precompression stress data, while little data on compression index or recompression index are available. Most precompression stress data were derived from the topsoils of conventionally tilled arable fields, which is not compatible with knowledge that subsoil compaction is a serious problem. The data compilation unveiled considerable variations in soil compression test procedures and methods for calculating precompression stress across different studies, and a concentration of data at soil moisture conditions at or above field capacity. The random forest models exhibited unsatisfactory predictive performance although they performed better than previously developed models. Models showed slight improvement in predictive power when the underlying data were restricted to a specific precompression stress calculation method. Although our database offers broader coverage of precompression stress data than previous studies, the lack of standardization in methodological procedures complicates the development of predictive models based on combined datasets. Methodological standardization and/or functions to translate results between methodologies are needed to ensure consistency and enable data comparison, to develop robust models for precompression stress predictions. Moreover, data across a wider range of soil moisture conditions are needed to characterize soil mechanical properties as a function of soil moisture, similar to soil hydraulic functions, and to develop models to predict the parameters of such soil mechanical functions.

The bearing capacity of traditional prestressed high-strength concrete (PHC) pipe pile is hampered by the poor mechanical properties of surrounding soil in soft soil areas, and the PHC nodular pile can improve the behavior of pile foundation in soft soils. The PHC nodular pile installation process will induce larger disturbance to the surrounding soil compared to the PHC pipe pile, and there is little research on the installation effect of the PHC nodular pile. In this paper, the coupled Eulerian-Lagrangian (CEL) finite element method was adopted to simulate the penetration process of PHC nodular piles and pipe piles in soft soil. The radial stress and displacement in soil induced by the PHC nodular pile and pipe pile and the soil resistance at different parts of the PHC nodular pile were analyzed. The simulation results showed that the penetration resistance of the PHC nodular pile was larger than that of the PHC pipe pile. The penetration resistance of PHC nodular piles was mainly provided by the pile shaft resistance. The uplift height of soil surface caused by the PHC nodular pile and pipe pile penetration was approximately the same. The influence range of compaction effect for PHC nodular pile and pipe pile was both concentrated on 10R (R is the pile diameter).

Over the past decade, there have been 45 tailings storage facility (TSF) disasters worldwide resulting in fatalities, serious environmental damage, and the destruction of entire ecosystems. These failures often stem from substandard design or operational practices. Many TSFs are constructed in regions associated with intrusive mafic rocks such as gabbro, norite, pyroxenite, and anorthosite, which are commonly found alongside platinum group metals in areas like the Bushveld Igneous Complex in South Africa and the Great Dyke in Zimbabwe. The stability of these structures can be significantly influenced by the residual soils present at the construction sites. Residual soils, both cohesive and non-cohesive, contain varying quantities of different minerals, which can impact the compaction characteristics and, consequently, the stability of the TSF foundations. Cohesive soils rich in clay minerals, such as kaolinite and smectite, exhibit properties that can hinder effective soil compaction. The expansive nature of smectite due to its ability to absorb large amounts of water and host free exchangeable cations counteracts the compaction process, reducing soil stability. Soil compaction is a complex process influenced by several factors, including compaction effort, method, water content, particle size distribution, and mineralogy. This study aimed to analyse these factors using a series of laboratory tests, including foundation indicators, MOD AASHTO compaction testing, and X-ray diffraction analysis, on residual soils from two TSF construction sites. The findings revealed that soils with high clay content tend to retain more water and have a higher optimum water content, adversely affecting their compaction properties. This study highlights the critical need to consider the mineralogical composition and weathering effects of residual soils in the design and construction of TSFs. By improving our understanding of these factors, we can enhance the stability of TSF foundations, reducing the likelihood of future failures. The insights gained from this research highlight the importance of thorough geotechnical assessments in the successful design and maintenance of TSFs.